Fluid pressure control mechanism



April 26, 1938. 1.. A. MAJNERI FLUID PRESSURE CONTROL MECHANISM Filed Oct. e, 1935 2 Sheets-Shea; 2

0 uuw 1 M $5 E 4 fi m w L Arron/5y Patented Apr. 26,1938

UNlTED STATES FLUID rnnssrmn .OONTBOL MECHANISM Ludwig A. men, Detroit, Mich. Application October 6, 1933; Serial No. 692,508

6 Claims. This invention relates to a fluid pressure control mechanism and is specifically illustrated as embodied in a control mechanism for hydraulic brakes, particularly applicable to airplanes.

One object of this invention is'to provide a mechanism which will permit instant application of the brakes by the operator and to retain the mechanism in applied position after the operator has released the operating mechanism.

Another object of the invention is to provide a holding mechanism which may be quickly released, thereby instantly releasing the fluid pres- .sure on the brakes.

Other objects and advantages of the invention will more fully appear from the following description taken in connection with the accompanying drawings, in which:

Fig. 1 is a diagrammatic view illustrating the salient features of the invention and its application to a support.

Fig. 2 is a side elevation of the device shown in normal position.

Fig. 3 is a sectional view taken on line lII-IlI of Fig. 2.

Fig. 4 is an end view of my improved mechanism shown in Figs. 1, 2, and 3.

Fig. 5 is a view corresponding to Fig. 2 butshowing the parts in an operated position.

Fig. 6 is a side elevation of the parts shown in Fig. 5.

Referring to the drawings, I have shown a casing or sleeve member I which extends substantially the length of the mechanism. A cylindrical member I2 is mountedin the sleeve M for recip rocation and is provided with a closed end which consists of a plug I4. I2 is provided with a piston l6. Reciprocably mounted thereon is a shoulder l6 forming a stop limiting the outward movement of the piston IS in the cylindrical member l2. A packing member 26 is provided on a piston-rod 22 which extends through the plug l4. Anjannular recess 24 is provided in the piston rod to receive a split washer 26 which forms an abutment for a coil spring 28 positioned between the split washer 26 and a packing member 30 abutting against the plug member l4. outwardly beyond the shoulder I8 is provided a chamber 32 having a piston 34 therein which is resiliently urged inwardly by a coil spring 36 abutting against a cap member 38 which closes the outer end of the cylindrical me1nber l2. A fitting 40 is provided in the wall of the cylindrical member I2 which affords a communication to the pressure chamber 42. Fluid is supplied through this fitting 40 into the chamber The cylindrical member 42, preferably lubricant such as commonly used in .hydraulic cylinders. The lubricant in this chamber is fed through an opening, in the piston rod 22 through holes 43 in the piston l6 into the reserve chamber 32. When the reserve chamber 32-is empty the piston 34 is extended inwardly with the bottom edge 46 showing through a slot 48, indicating the position of the piston 34, and consequently the amount of fluid in'the reserve chamber 32. As more lubricant is supplied through the fitting 40 the piston34 moves outwardly against the resistance of the spring 36 until the end of the piston 46'strlkes the cap member 38. It will thus be understood that at all times the reserve chamber 32 is under a slight pressure caused by the spring 36 resiliently-urging the piston 34 inwardly.

When an extending force is applied the cylindrlcal member i 2 and all parts integral with it move in relation to sleeve l0 which is attached to the structure and in relation to all parts which are prevented from axial movement in relation to sleeve l0, including piston rod 22 and piston l6. This motion tends to decrease the volume of chamber 42, causing arapid rise of pressure in chamber 42 .when the mechanism is in operation. The area of the passage 44 is made sufficiently small so that the pressure in chamber 42 rises zfaster than the fluid can escape through passage 44 into chamber 32. This pressure rise causes cup 26 and piston I6 to move axially forcing the piston against I2 thereby closing the passage 44,

A-fltting '50 is provided bn the side of the cylinder member l2 opposite to the fitting 46 for conducting the fluid pressure from the chamber 42 to any operating mechanism, such as hydraulic brakes.

Adjacent the inner end of the cylindrical member I2 is a fitting 52 which carries a transverse member 54. The transverse member 54 extends through the wall of the sleeve member l0 and moves therewith during the relative movement of the sleeve member ID and the cylindrical member l2. Another transverse member 56 is providedv in the sleeve I 0 at its outer end. This transverse member has relative movement with the sleeve I 6, there being providedv slots 58 which permit the member '56 to move axially relative to the" sleeve III. The piston rod 22 is provided at its outer end with a nut 60 which acts as an adjustable stop limiting the outward movement of the member 56. The outer end of the sleeve [6 is provided with a cap 62 having a projection 64 V which may be secured to a support 66. The cap 88 is provided with an extension 88 to which is secured an operating lever I0.

When the cylindrical member I2 is moved relative to the sleeve I0, for example, by a pull on the operating lever II, it will be understood that the pressure chamber 42 is reduced involume by the relative movement, of the piston 10 and cylindrical member I2. During this movement the open- 7 ing 44 in the piston rod 22 is closed by the limited lost motion between a shoulder 12 on the rod 22 and the piston I6. As the closed end of the cylindrical member moves toward the piston It the resistance is taken through the piston I8, piston rod 22, transverse member 56, arms 84, transverse member 58, and thence through the sleeve I0 to the support 88.

;When the member 80 is in the position as shown, in Figs. 5. and 6 the resistance is taken through the piston I6, piston rod 22, transverse member 56 to a relatively stifl spring I4, and from there to the transverse member 04, and thence through the sleeve III to the support 88. 1

Two members 88 are pivotally mounted on the transverse member I held in place by a nut 82 screw threaded in a member 58. The two members 80 each comprises an arm 84 which extends from the pivoted support at 82 to a member 86 carried by the transverse member 58. The member 88 is held in place by a bolt 88 screw threaded into the member 88. One of these levers 80 is provided at the opposite sides of the cylindrical member I2, and for the'purpose of description only-one lever will be described, the other one being a duplicate of the flrst.

Duringnormal operation 01 this device the arm 84 remains in the position shown on the drawingsforming a rigid connection between the transverse members 58 and 88, causing the spring II to be inert. Another arm 80 is provided on the member 88 to receive a control'mechanism. This control mechanism consists of a flexible tubular member 82 secured to a support, such as v the instrument board 88 and the arm 88. A wire 8 is extended through the instrument board and the flexible tube 82. One end of the wire is accured to a support 08 on the sleeve "and the opposite end of the wire is provided with an operflexible spring ll.

0n the opposite side of the pivot a: 1 have providedanother extension I82 consisting oi aplurality oi p rtions Ill located at varying lengths from the pivot 82. These portions Ill are nor-1 mally in the'position shown in Fig. 2 but whenthe lever 88 is swlmg in the direction indicated by the arrow A one of the portions I04 engages a projection I08 the cylinder. I2, as shown in Pig. 8. Bythis mechanism! have provided a variable stop which m-events return movement of the piston relative to the cylindrical. member-I2, providing a means'tor varying the return stroke of the 'pistomthm permitting the operator to maintain: the brakes applied without manual operation. .:When theann I82 is in a position so that ,one oi-theportions-Iflengages thestop I08 the spring .14 is in operation, urging with a great deal 78' or some, thezplston away from the outer end of the cylindrical member. The moment pressure is applied through the control I0 the piston It moves relative to the cylindrical member I2,

thereby releasing the pressure of the stop I08 on one of the projections I04 and the spring 8| returns the lever 80 to its normal position, as indicated on the drawings in Fig. 2. The, spring II then releases the brakes.

During the operation of the device the pressure in the chamber 82 is created by pulling on the control II which may be attached to any suitable connection (not shown). The pull is transmitted through the cylindrical member I2 and sleeve I0.

The force applied on the control I0 is transmitted to the piston It by means of the liquid in 42 and spring 28, and from I8 by-22, 60, 56, 84, 58 toI0 and to the flxed support 88. If it is'desired to retain the fluid under pressure in the chamber 42 the arm 84 is swung out of the path of the member 88 and the arm I02 is swung into the path of the stop I06 when-the chamber 02 is under pressure. Such movement of the arms 80 and 88 causes the pull to be taken through the heavy coil spring 1,4, the transverse member moving relative to the sleeve in the slots 58. When the arm I02 is returned to its normal position the heavy spring 14 immediately releases the pressure in the chamber 42.

The reserve chamber 22 between the and piston I8 is under a slight pressure caused by the compression spring 88 urging the piston 88 inwardly. As the amount of fluid in the chamber 32 is reduced the piston fl-moves inwardly with its open end 46 showing through the slot 48; thus .the position of the pistonindicates the amount of fluid in the reserve chamber 32.

It will be understood that various changes, in-

cluding the size, shape and arrangement of parts may be made without departing from the spirit of my invention. The use of the mechanism'may be brakes and it is not my intention to limit the scope of my invention other than by the terms of the appended claims.

What I claim is: V

-1. In a fluid pressure control mechanism, the combination of asleeve, of a cylindrical member having a clomd inner end reciprocable in said s piston 88 applied to various devices other than hydraulic sleeve, a piston in said cylindrical member i'orminga fluid chamber between said piston and the closed inner end of said cylindrical member, a piston rod extending through said fluid chamber and the closedend of said cylindrical member, an outer transverse member carried by said rod limited for axial movement relative to said sleeve .in one direction but free for relative movement in an opposite direction, an inner transverselnember carried by said sleeve, resilient means between said inner and. outer transverse members,

and means for preventing axial movement of the transverse members.

2. In a fluid pressure control mechanism, the

combination of a sleeve, 01 a cylindrical member.

having a closedinner end reciprocable in said sleeve, a piston in said cylindrical member forming a fluid chamber between said piston and the .closed inner end of said cylindrical member, a

piston rod extending through said fluid chamber and the closed end of said cylindrical member, an outer transverse member carried by said rod limited for axial movement relative to said sleeve in one directionbut free for relative movement in an opposite direction, an inner transverse member carried by said sleeve, resilient means between inner outer transverse memamount of relative movement between said stop and said sleeve.

3. In a fluid pressure control mechanism, the combination of a sleeve, of a cylindrical member having a closed inner end reciprocable in said sleeve,.a piston in said cylindrical member forming a fluid chamber between said piston and the closed-inner end of said cylindrical member, a piston rod extending through said fluid chamber and the closed end of said cylindrical member, an outer transverse member carried by said rod limited for axial movement relative to said sleeve in one direction but free for relative movement in an opposite direction, an inner transverse member carried by said sleeve, resilient means between said inner and outer transverse members, means for preventing axial movement of transverse members, a stop carried by said cylindrical member extending through said sleeve having relative movement therewith, and means for limiting the amount of relative movement between said stop and said sleeve.

4. In a fluid pressure control mechanism, the combination of a cylindrical member, of a piston within said cylindrical member forming a fluid chamber between the piston and the end of said cylindrical member, a piston rod connected to said piston extending through the end oi! said cylindrical member and therebeyond, an abutment on the end of said rod, a member between the end of said cylindrical member and said abutment, resilient means between said abutment and said member, an arm pivotally mounted on said member having an extension on one side of its pivot for engagement with said abutment and an extension on the other side of its pivot for engagement with said cylindrical member, and means for swinging said arm about its pivot to position the extensions, one between said abutment and said member, or the other between said member and said cylindrical member.

5. In a fluid pressure control mechanism, the combination of a cylindrical member, of a piston within said cylindrical member forming a fluid chamber between the piston and the end of said cylindrical member, a piston rod connected to said piston extending through the end of-said cylindrical member and therebeyond, an abutment on the end of said rod, 2. member between the end of said cylindrical member and said.

abutment, resilient means between said abutment and said member, an arm pivotally mounted on said member having portions located at varying distances from its pivot each portionadapted for engagement with said cylindrical member, and

' means for swinging said arm to position any selected portion between said member and said cylindrical member.

said piston, a resilient means between said piston and the closed end of said cylindrical member for moving said cylindrical member relative to "said housing, and means carried by said housing and said cylindrical member for holding said pis-' ton and said cylindrical member in a predetermined relative position and preventing movement of said piston by said resilient means.

LUDWIG A. 

